The present invention relates to a data storage device, a connector, and a magnetic disk drive. In particular, the present invention is suitable for a hard disk drive provided with a serial Advanced Technology Attachment (SATA) connector.
Devices using various types of media such as optical disks and magnetic tapes are known as information recording and reproducing devices. Among them, hard disk drives (HDDs) have become popular as storage devices for computers to such an extent that they are one of the storage devices indispensable for today's computers. Further, not limited to computers, their application is widening more and more due to the superior characteristics with the advent of moving picture recording/reproducing devices, car navigation systems, removable memories for digital cameras and so on.
Each magnetic disk used in HDDs has a plurality of tracks formed concentrically and each track is partitioned into a plurality of sectors. In each sector, sector address information and user data are stored. Either data written to a sector or data read from the sector is enabled by a magnetic head which accesses the desired sector according to the sector address information. A signal read out from a magnetic disk through a data read operation is subjected to waveform shaping, decoding processing and other prescribed signal processing by a signal processing circuit before transmitted to the host. Likewise, data transferred from the host is subjected to prescribed signal processing by a signal processing circuit and then written to the magnetic disk.
As an interface for data transfer between a host such as a computer and an HDD there usually is employed such a protocol as SCSI (Small Computer System Interface) or ATA ( Advanced Technology Attachment) Interface. In particular, from the standpoint of improving the interface function and attaining a reduction of cost, the ATA interface is utilized in many computers and is also widely utilized as an interface in other types of storage devices such as optical disk storage devices. With the demand for improving the recording density and improving the performance, the demand for the data transmission rate of the ATA interface is becoming more and more strict. Therefore, ATA interface (serial ATA) using serial transmission instead of the conventional parallel transmission has been proposed.
A standard for serial ATA is being established by “Serial ATA Working Group.” In “Serial ATA II: Extensions to Serial ATA 1.0 Specification,” several techniques not found in the conventional parallel ATA are adopted. With the change from parallel to serial transmission method, the structure of the connector for connecting the HDD to a host such as a PC is also being modified greatly.
For example, in Patent Literature 1 (Japanese Patent Laid-open No. 2003-257567), an impedance tuning type connector for diminishing the percent of product defect is proposed as a connector conforming to the Serial ATA Interface. The impedance tuning type connector is provided with an insulating housing and plural signal terminals disposed in the insulating housing, each terminal having a connector portion and a pin portion. A pit portion is disposed between two adjacent contact portions of signal terminals and one signal terminal is separated with air from the adjacent signal terminals. Since the dielectric constant of air is lower than that of plastics, the capacitance between the two signal terminals decreases, but the impedance between them is presumed to become high.